SEAT Workshop Service and Repair Manuals > Leon Mk2 > Power unit | 4LV Injection and Ignition System | Mixture preparation system, electronic inj.,Gas | Jet profile and leakage: testing | Intake system: testing for leakage (infiltrated air)

Test process

Note!

t	Due to the decompression in the intake system, the leak detection spray is drawn in with the infiltrated air. The spray reduces the flammability of the mixture. This causes engine revs to fall and a variation in lambda probe voltage.

t	Carefully follow all safety instructions on the container.

–	Connect the -V.A.G. 1551- (-V.A.G. 1552-). Start the engine and enter the “address code” 01 to select the engine control unit. (Fault reader: connecting and selecting the engine control unit → Chapter.)

Reading on display:

–	Press 0 and 8 for the function “Read measured value block” and confirm the entry with the Q key.

Rapid data transmission             HELP

Select function XX

Reading on display:

–	Press 0, 3 and 3 for “display group 33” and confirm the entry with the Q key.

Read measured value block           HELP

Enter display group no. XXX

–	Watch the lambda probe voltage in display field 2.

–	Apply leak detection spray systematically to the components of the intake system.

If the engine revs fall or the lambda probe voltage varies:

–

Press →.

–	Press 0 and 6 for the function “End transmission” and confirm the entry with the Q key.

–	Switch off the ignition.

–	Test the sprayed area of the intake system for leaks and eliminate the possible fault.

If the engine revs and the lambda probe voltage do not vary:

–

Press →.

–	Press 0 and 6 for the function “End transmission” and confirm the entry with the Q key.

–	Switch off the ignition.

Read measured value block      33      →

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